The present invention relates generally to agricultural implements having a plurality of wing sections which are foldable between field-working and transport positions, and more specifically, to an implement having foldable inner and outer wing sections and latching structure for securing the wing sections together as they are moved between the field-working and transport positions.
Multi-sectioned implements which are foldable to reduce implement width for transport have become increasingly popular. Implements such as exemplified in U.S. Pat. Nos. 3,948,327 and 3,967,684, of common ownership with the present invention, include a horizontally disposed main frame section pivotally supporting an inner wing frame for rocking between an outwardly extending field-working position and an upwardly extended transport position. An outer wing frame is pivotally connected to the outer end of the inner wing frame for rocking approximately 180 degrees between an outwardly extended unfolded position and a folded position generally alongside the wing frame. The outer wing frame is first folded over the inner wing frame, and then the inner wing frame is rocked upwardly to the transport position. During transport, it is necessary to keep the outer wing generally parallel to the inner wing so that structure such as walking beam wheels which extend inwardly from each of the outer wing frames in the transport position do not strike each other as the implement moves over the ground. To lock the outer wing frames with respect to the inner wing frames without additional hydraulic circuitry or expensive latching mechanisms usually requires that the operator leave the tractor and insert pins or other securing structure. This can be timeconsuming and inconvenient for the operator.
It is therefore an object of the present invention to provide an improved multi-sectioned folding implement with structure for locking the wing frames in position during transport. It is a further object to provide such an implement having an improved latching system which is simple in construction and operation.
It is a further object of the invention to provide a multi-section folding implement having inner and outer wing frames wherein the wing frames are latched together automatically as the frames are rocked to the transport position without the operator having to leave the tractor to pin or unpin latching devices. It is another object of the invention to provide such a structure which is relatively simple and inexpensive in construction and yet which effectively secures the wings in position. It is a further object to provide such a structure which automatically unlatches as the wing frames are rocked toward the field-working positions.
It is still another object of the present invention to provide a multi-sectioned folding implement having inner and outer wing frames located at opposite ends of a main frame section and including latching structure for automatically latching the outer wing frame to the inner wing frame on each side of the implement as the inner wing frame is rocked upwardly toward the transport position to prevent interference between the outer wing frames during transport. It is a further object to provide such a structure which unlocks the wing frames automatically as the inner wing frames are rocked back toward the field-working position. It is a further object to provide such a structure wherein latching and unlatching of the wing frames is accomplished automatically as the inner wing frames are rocked with respect to the main frame. It is still another object to provide such a structure wherein the latching mechanism is biased by gravity without need for additional hydraulic circuitry or other complicated structure.
In accordance with the above objects, an implement constructed according to the present invention includes a pair of inner wing frames pivotally connected to the outer ends of a main frame, and outer wing frames pivotally connected to the outer ends of the inner wing frames. The outer wing frames are foldable approximately 180 degrees from outwardly unfolded positions to positions generally overlying the inner wing frames. After the outer wing frames are folded, the inner wing frames are rocked upwardly toward a generally upright but slightly over center transport position. To prevent the outer wing frames from rocking with respect to the inner wing frames during transport, latching structure for securing the outer wing frames in generally parallel relationship with respect to the inner wing frames is provided. The latching structure includes a gravity-activated latch pivotally connected to a bracket on the inner wing frame, and a bracket on the outer wing frame which contacts the inner wing frame bracket. The latch has a hooked portion and a center of gravity which shifts relative to the pivotal axis to cause the latch to automatically gravitate to a locking position wherein the hooked portion moves over the outer wing bracket as the inner wing frame rocks toward the upright position. The latch maintains the inner and outer wing frames generally in parallel relationship during transport to prevent interference between the outer wing frames and the wheel assemblies projecting therefrom during transport. As the inner wing frame is rocked back toward the field-working position, the center of gravity of the latch changes relative to the pivotal axis of the latch to automatically cause the latch to fall away from the outer wing frame bracket, thereby releasing the outer wing frame relative to the inner wing frame for unfolding toward the field-working position. Therefore, the latching and unlatching of the wings is accomplished without the operator leaving the tractor to pin or unpin any latching devices or the like. The gravity-actuated latch arrangement is relatively simple and effective, and provides automatic locking and unlocking of the wing frames.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the description which follows and from the drawings.